I dropped and busted the casing of a portable battery pack and now I am thinking of installing that battery in my hard case next to the GL1100 battery. If I install it fully charged the battery and electrical system should not be effected. I am worndering if the added amps avaible would cause a problems with the regulator or anything else.

I don't know that I would just hook it up in parallel with your existing battery. The two batteries are going to charge at different rates. If you had a secondary charge controller (like used for a trailer) you could use that. However, if it is severely discharged, it along with the main battery (after a start discharge) could easily overwhelm the charging system of your bike.

ok thanks
will have a few more questions soon getting the old girl out and fixing her up some my son rode it for a year and I don't know exactly what shape he left it in before going in the service. I know the horns are missing lol why I don't know